New Insights into Chronic Fatigue Syndrome's 'Brain Fog'

Researchers believe the discovery of a unique pattern of immune molecules in the cerebrospinal fluid of people with chronic fatigue syndrome may explain the “brain fog” that often accompanies the illness.

Chronic fatigue syndrome (CFS) is the common name for a group of debilitating medical conditions characterized by persistent fatigue and other specific symptoms, including cognitive dysfunction, that persists for a prolonged period.

As published in the journal Molecular Psychiatry, Mady Hornig, M.D., and colleagues from Columbia University’s Mailman School of Public Health, used immunoassay testing methods to measure cerebrospinal biomarkers.

They hoped to discover insights into the basis for the cognitive dysfunction or “brain fog” as well as new hope for improvements in diagnosis and treatment.

The researchers assessed the levels of 51 immune biomarkers called cytokines of 32 people who had experienced myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) for an average of seven years.

They also measured markers in 40 individuals with multiple sclerosis (MS), and 19 non-diseased controls.

Investigators found that levels of most cytokines, including the inflammatory immune molecule, interleukin 1, were depressed in individuals with ME/CFS compared with the other two groups.

This finding matched what was seen in a blood study of patients who had the disease for more than three years. One cytokine, eotaxin, was elevated in the ME/CFS and MS groups, but not in the control group.

“We now know that the same changes to the immune system that we recently reported in the blood of people with ME/CFS with long-standing disease are also present in the central nervous system,” said Hornig.

“These immune findings may contribute to symptoms in both the peripheral parts of the body and the brain, from muscle weakness to brain fog.”

“Diagnosis of ME/CFS is now based on clinical criteria. Our findings offer the hope of objective diagnostic tests for disease as well as the potential for therapies that correct the imbalance in cytokine levels seen in people with ME/CFS at different stages of their disease,” said W. Ian Lipkin, M.D.

Source: Columbia University’s Mailman School of Public Health